Chubb, the largest US non-life insurer by market capitalisation, has approached rival Hartford Financial Services Group with an unsolicited $23.2bn takeover offer, in what could be the first mega-deal in an industry battered by losses stemming from the coronavirus pandemic.

The company led by Evan Greenberg said it had offered $65 per share to buy Hartford, a 13 per cent premium on the Connecticut-based group’s closing share price on Wednesday before news of a potential approach emerged on Thursday. The offer was mostly cash and some stock, said Chubb, without providing exact details.

Hartford said its board of directors was considering a non-binding proposal from Chubb. However, according to people briefed on the matter, the company’s executives were unimpressed because the premium was too low.

After Bloomberg first reported Chubb’s approach, shares in Hartford rose 18.7 per cent to $68.20 to give it a market value of $24.4bn — above the offer made by Greenberg’s company.

There are no active talks between the two sides, said the people briefed on the matter. They added that it was unclear whether a deal could be reached since any combination would face significant regulatory risks.

Chubb said in a statement that it believed a combination “would be strategically and financially compelling for both sets of shareholders and other constituencies”. 

The son of Maurice “Hank” Greenberg, who turned AIG into a financial powerhouse over four decades, Evan Greenberg has spent several years building his own insurance empire. His biggest deal was the $30bn combination of Ace and Chubb in 2015.

A deal would give Chubb greater scale in an industry that is still recovering from pandemic-related losses. Insurers have paid out billions of dollars in claims on a variety of policies, ranging from business interruption to event cancellation, and there could be more to come. According to some estimates, total claims from the pandemic across the global insurance industry will top $100bn. 

Those losses have prompted insurers to push up prices for cover, especially on commercial insurance policies, leading some investors to expect healthy future returns from the industry. 

Hartford’s biggest business is in commercial lines insurance, where price rises over the past year have been the steepest. It also sells personal insurance such as motor — where claims fell last year as drivers stayed at home — and has an employee benefits business. 

Hartford is no stranger to big dealmaking, bulking itself up three years ago with the $2.1bn acquisition of Navigators, a specialist commercial insurer. The previous year it sold a book of life insurance business to a consortium led by Bob Diamond’s Atlas Merchant Capital.